As of December 31, 2008, there were 252 children and adolescents aged 0-19 and 917 young adults aged 20- 29 with a reported HIV/AIDS diagnosis living in the city of Baltimore. The Pediatric and Adolescent HIV/AIDS Program (PAHAP) in the Johns Hopkins Children's Center in collaboration with its Center for Child and Community Health Research (CCHR) and the Adolescent Medicine Program is applying to be an Adolescent Medicine Trials Unit (AMTU) in the Adolescent Medicine Trials Network for HIV/AIDS Interventions (ATN). The PAHAP offers comprehensive medical, psychosocial, outreach and social services to HIV-positive, HIV-affected, and at-risk adolescents in the context of a large, productive research institution located in East Baltimore City. The proposed Principal Investigator of the Johns Hopkins AMTU, Dr. Jonathan Ellen, is Professor and Vice Chair in the Department of Pediatrics at the Johns Hopkins University School of Medicine and is board certified in Pediatrics and Adolescent Medicine. He is Principal Investigator on the IMPAACT CTU site at Johns Hopkins and he co-directs PAHAP and the Adolescent Medicine Program. In addition to his work at these clinical programs, Dr. Ellen is Director of the CCHR. With his direction, the CCHR has designed and managed independent adolescent research projects and successfully participated in multi-site collaborative studies. The CCHR's infrastructure is responsible for many of the treatment and prevention programs provided in the PAHAP and the community. Further, in his capacity as Medical Director for the Baltimore City Health Department (HCHD) Syphilis Elimination Program, Dr. Ellen has forged a strong reciprocal relationship between the CCHR, PHAP and the BCHD that insures continued identification and referral of HIV-infected and at-risk adolescents and young adults to the PAHAP. Based on the combined expertise of the PAHAP and the CCHR, the use of innovative programs in reaching disenfranchised youth, demonstrated success in recruiting and retaining youth in trials, and productive collaborations with our community, we believe that the Johns Hopkins AMTU would offer significant operational and scientific contributions to the ATN agenda. RELEVANCE: The Pediatric and Adolescent HIV/AIDS Program (PAHAP) proposes to establish an Adolescent Medicine Trials Unit (ATU) in the Adolescent Medicine Trials Network for HIV/AIDS Interventions (ATN). The expertise of the investigators and experience of the staff make the PAHAP well qualified to be an effective ATU and contribute to the ATN.